Electrocorticography reveals thalamic control of cortical dynamics following traumatic brain injury
Sima Mofakham, Adam Fry, Joseph Adachi, Patricia Stefancin, Timothy Q. Duong, Jordan R. Saadon, Nathan J. Winans, Himanshu Sharma, Guanchao Feng, Petar M. Djurić, Charles B. Mikell
Abstract
The return of consciousness after traumatic brain injury (TBI) is associated with restoring complex cortical dynamics; however, it is unclear what interactions govern these complex dynamics. Here, we set out to uncover the mechanism underlying the return of consciousness by measuring local field potentials (LFP) using invasive electrophysiological recordings in patients recovering from TBI. We found that injury to the thalamus, and its efferent projections, on MRI were associated with repetitive and low complexity LFP signals from a highly structured phase space, resembling a low-dimensional ring attractor. But why do thalamic injuries in TBI patients result in a cortical attractor? We built a simplified thalamocortical model, which connotes that thalamic input facilitates the formation of cortical ensembles required for the return of cognitive function and the content of consciousness. These observations collectively support the view that thalamic input to the cortex enables rich cortical dynamics associated with consciousness.